JP2002178434A - Photocatalytic sheet with protecting layer and manufacturing method for photocatalytic sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a photocatalytic layer from being flawed so that the performance of the photocatalytic layer having a photocatalytic action is maximized, when a pressure-sensitive adhesive layer is formed of a photocatalytic sheet and the photocatalytic sheet with the pressure-sensitive adhesive layer is attached to an adherend. SOLUTION: The photocatalytic sheet with a protecting layer is formed of a sheet-like base material, the photocatalytic layer containing a titanium oxide as an essential component and a substantially non-sticky heat-melting resin layer to the photocatalytic layer, laminated in that order. Alternatively, the photocatalytic sheet with a protecting layer is formed of the sheet-like base material, the photocatalytic layer containing the titanium oxide as an essential component, the substantially non-sticky heat-melting resin layer to the photocatalytic layer and a plastic film which does not melt at a melt temperature of the heat-melting resin layer, laminated in that order.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called so-called light-receiving device which exhibits a high degree of hydrophilicity by receiving light and exhibits various functions such as a deodorizing function, an organic substance decomposing function, a water decomposing function, and a sterilizing function. A photocatalyst sheet formed by laminating photocatalyst layers, in particular, a layer for protecting the photocatalyst layer, which is the basis of function development, is formed on the photocatalyst layer until various functions as described above are developed according to various purposes and applications. And a photocatalyst sheet laminated on the photocatalyst sheet.

[0002]

2. Description of the Related Art In recent years, when light is irradiated on a photoconductive material,
The photo-semiconductor substance decomposes organic matter, decomposes water, decomposes and removes environmental pollutants in water and air, deodorizes, and sterilizes (hereinafter referred to as photocatalytic function or photocatalytic action) ), And has attracted attention in many applications and fields.

For example, Japanese Patent Application Laid-Open No. 5-154473 discloses a photocatalytic action of a photoconductive substance such as titanium oxide as a method for effectively performing oxidative decomposition and sterilization of organic substances contained in a fluid. A photochemical reaction processing method is disclosed. Japanese Patent Application Laid-Open No. 9-226042 discloses a method in which a film substrate surface of a laminated film having a surface layer containing photocatalyst particles on one surface of a film substrate is adhered to a substrate, that is, an adherend, A method for irradiating a photocatalyst with light by irradiating a surface layer containing the compound with light to make the surface of a substrate (adherend) hydrophilic, and a laminated film used in the method are disclosed. Further, JP-A-9-227161 discloses that a window glass directly provided with a surface layer containing photocatalytic oxide particles is irradiated with light, or a window glass provided with a surface layer containing photocatalytic oxide particles. Attaching the film to be worn to the window glass, irradiating the window glass with light after the application, and expressing the hydrophilicity in the surface layer in response to the excitation of the photocatalytic oxide particles, the window glass There are disclosed methods for preventing fogging and for facilitating easy cleaning of window glass, and a window glass and a film for attaching a window glass used in the method. In addition to these, JP-A-9-59042, JP-A-9-227169, JP-A-10-156190, and the like disclose various methods of using a material having photocatalytic performance.

In general, in order to produce a film having a photocatalytic function by utilizing the photocatalytic function of a photoconductive substance, a plastic film as a sheet-shaped base material is subjected to a corona discharge treatment, and a primer coating made of a silicone resin is applied. After coating and drying, a silicone-based hard coat agent is applied on the primer coating and dried to form a silicone-based hard coat layer.After the silicone-based hard coat layer is subjected to corona discharge treatment, oxidation is performed. Titanium-containing coating composition (eg, anatase-type titanium oxide sol, silica sol and ethanol dilution of trimethoxysilane)
Is applied and cured by heat treatment.

A layer having a photocatalytic function (hereinafter, referred to as a photocatalytic layer) requires that a substance having a photocatalytic function, for example, titanium oxide, be exposed to the outside of the photocatalytic layer as much as possible in order to sufficiently exhibit the function. However, if the titanium oxide is to be exposed to the outside as much as possible, the surface roughness of the photocatalyst layer becomes large and the photocatalyst layer becomes more porous. As a result, the film surface of the photocatalyst layer becomes brittle and easily scratched. Was in a state. Also, in order to immobilize a photoconductive substance having a photocatalytic action represented by titanium oxide on a sheet-like substrate, an organic binder decomposed by the action of the photocatalyst cannot be used. It is necessary to select a binder made of an inorganic material that is difficult to be used. However, since the inorganic binder itself was brittle, the film surface of the photocatalyst layer was further brittle and was in a state of being easily scratched. When the photocatalyst layer is damaged, the damaged photocatalyst layer not only does not exhibit its function even when irradiated with light, but also receives moisture and the like from the scratch, and the entire photocatalyst layer and the sheet In some cases, the photocatalyst layer may be detached from the substrate in the worst case.

Incidentally, a photocatalyst sheet (film) having a photocatalyst layer is coated with an adhesive or the like on the surface on which the photocatalyst layer is not laminated, that is, on the back surface of the photocatalyst sheet, to form a sheet with an adhesive layer. Is often attached to an adherend and used. Or form an adhesive layer on a release sheet,
The pressure-sensitive adhesive layer and the back surface of the photocatalyst sheet are brought into contact with each other, and the two sheets are laminated to form a sheet with a pressure-sensitive adhesive layer. The sheet may be attached to an adherend and used. However, regardless of whether the pressure-sensitive adhesive is directly applied to the back of the photocatalyst sheet or the pressure-sensitive adhesive layer provided on the release sheet is laminated, the photocatalyst layer is damaged by a guide roll of a coating machine in any case. I could enter. Alternatively, if the photocatalyst layer is provided on the non-adhesive layer side of the sheet-like base material on which the adhesive layer is provided in advance, the occurrence of scratches when the adhesive layer is provided later on the back of the photocatalyst sheet as described above can be prevented. However, if the photocatalyst sheet with the adhesive layer is attached to an adherend such as a rearview mirror or glass, the photocatalyst layer must be rubbed with a squeegee or the like due to the need for pressure bonding. Outbreaks were inevitable.

[0007] In order to prevent the occurrence of these scratches, when a photocatalyst sheet with an adhesive layer is obtained, or when a photocatalyst sheet with an adhesive layer is adhered to an adherend, a PET film or the like is overlaid on the photocatalyst layer, A method of protecting the photocatalyst layer by attaching an adhesive film to the photocatalyst layer or the like has been implemented. However, in the former case, since the PET film and the photocatalyst layer are basically not bonded together, when the pressure-sensitive adhesive layer is laminated on the back of the photocatalyst sheet, or when the photocatalyst sheet is bonded to the adherend, the PET film or the like is used. Therefore, it was extremely difficult to stack the pressure-sensitive adhesive layer on the back surface of the photocatalyst sheet and to attach the photocatalyst sheet with the pressure-sensitive adhesive layer to the adherend. On the other hand, in the latter case, after attaching the photocatalyst sheet to the adherend,
When peeling the slightly adhesive film that protected the photocatalyst layer, a small amount of adhesive remains on the photocatalyst layer, although it is slightly adhesive,
As a result of the photocatalyst layer being contaminated before being excited and activated by light, there is a disadvantage that the expression of the photocatalytic function is significantly impaired. Therefore, there is a strong demand in the market for obtaining a photocatalyst sheet with an adhesive layer without damaging the photocatalyst layer, and for developing a photocatalyst sheet film with an adhesive layer that can be attached to an adherend without damaging the photocatalyst layer. Was.

[0008]

SUMMARY OF THE INVENTION The present invention provides a photocatalyst layer having a photocatalyst layer with a pressure-sensitive adhesive layer provided on the back surface thereof and a photocatalyst sheet with a pressure-sensitive adhesive layer attached thereto in order to maximize the performance of the photocatalytic layer having a photocatalytic action. An object of the present invention is to prevent the photocatalytic layer from being damaged when the photocatalytic layer is attached to a body.

[0009]

Means for Solving the Problems The present inventor has proposed a method of attaching a heat-fusible resin layer which can be easily peeled off without leaving a contaminant such as an adhesive on a photocatalyst layer after being adhered to an adherend. As a result, the present invention was completed. That is, the first invention is a photocatalyst sheet with a protective layer formed by laminating a sheet-shaped substrate, a photocatalyst layer, and a heat-meltable resin layer substantially non-adhesive to the photocatalyst layer in this order. The second invention provides a sheet-shaped substrate, a photocatalyst layer, a heat-meltable resin layer substantially non-adhesive to the photocatalyst layer, and a melting temperature higher than the melting temperature of the heat-meltable resin layer. A photocatalyst sheet with a protective layer obtained by laminating plastic films in this order. The third invention is the photocatalyst layer according to the first or second invention, characterized in that the photocatalyst layer contains titanium oxide as an essential component. The fourth invention is a photocatalyst sheet, wherein the pressure-sensitive adhesive layer and the release sheet are laminated in this order on a surface of the sheet-like substrate which is not in contact with the photocatalyst layer. A light contact with a protective layer according to any one of the inventions A sheet.

According to a fifth aspect of the present invention, a photocatalytic layer is laminated on one surface of a sheet-like substrate, and then a heat-fusible resin substantially non-adhesive to the photocatalytic layer is extruded onto the photocatalytic layer. A method for producing a photocatalyst sheet with a protective layer, comprising: laminating a photocatalyst layer on one surface of a sheet-like substrate, and then substantially non-adhesive to the photocatalyst layer. A method for producing a photocatalyst sheet with a protective layer, comprising melt-extruding and sandwiching a heat-fusible resin between a plastic film exhibiting a melting temperature higher than the melting temperature of the heat-fusible resin and the photocatalyst layer. The seventh invention is the method for producing a photocatalyst sheet according to the fifth or sixth invention, wherein the photocatalyst layer contains titanium oxide as an essential component.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The sheet-like substrate used in the present invention includes plastic film, metal foil, paper,
Synthetic paper, cloth, non-woven fabric, painted plate, metal plate and the like can be mentioned.
Among them, plastic films include polyethylene terephthalate film, polypropylene film, polyethylene film, vinyl chloride film, vinylidene chloride film, acrylic film, nylon film,
Examples include a fluorine film, a polyvinylidene fluoride film, a polycarbonate film, and a polyethylene-2,6-naphthalate film. The thickness of these plastic films is not particularly limited, but is suitably 6 μm to 2 mm, particularly preferably 12 to 200 μm. Among these plastic films, a biaxially stretched polyethylene terephthalate film is desirable. The surface of these plastic films may be subjected to surface treatment such as corona discharge treatment, flame treatment, plasma treatment, etc., but these surface treatments are not essential. It is preferable that nothing is provided on the surface of the plastic film, but a surfactant or an organic conductive agent such as a polymer electrolyte system, a UV absorber or a light stabilizer is applied in advance. It doesn't matter. Further, the above conductive agent or the like may be kneaded in a plastic film. Further, a vapor-deposited film such as a silica-deposited film, an aluminum-deposited film, an alumina-deposited film, or a sputtered film obtained by vapor-depositing or sputtering silica, aluminum, alumina, or the like on the various plastic films described above may be used.

Among the sheet-like substrates, examples of the metal foil include a stainless steel foil, an aluminum foil, and a copper foil. The synthetic paper is not particularly limited, and examples thereof include polyester-based synthetic paper and polypropylene-based synthetic paper. Paper, cloth,
There is no particular limitation on the nonwoven fabric. As a painted board,
A two-part or heat-curable acrylic, melamine, urethane, epoxy, or other paint is applied to a metal plate such as stainless steel, tin, galvanized iron, or the like and cured. No problem. The metal plate is not particularly limited, such as an iron plate, a stainless plate, a copper plate, a tin plate, and a galvanized plate.

In the present invention, when laminating a photocatalyst layer containing titanium oxide as an essential component on the sheet-like substrate, an easy-adhesion layer can be provided on the sheet-like substrate in advance. For example, a plastic film as a sheet-shaped substrate is subjected to corona discharge treatment, and then a primer coating composed of a silicone resin is applied and dried, and a silicone-based hard coating agent is further applied and dried on the silicone-based primer layer to obtain After applying a corona discharge treatment on the obtained silicone-based hard coat layer, a titanium oxide-containing coating composition is applied,
The photocatalyst layer can be formed by drying and heat curing.

The photocatalyst layer used in the present invention is:
Recently, many documents and patents (for example, Japanese Patent Application Laid-Open No. 9-2260)
42, JP-A-9-59042, JP-A-10
-195379, JP-A-10-156190, JP-A-9-227161, JP-A-9-227
169), when light (excitation light) having an energy (ie, shorter wavelength) larger than the energy gap between the conduction band and the valence band of the crystal is irradiated, A layer containing a substance capable of generating conduction electrons and holes by excitation of electrons (photoexcitation) in the band (hereinafter referred to as a photocatalyst). As the photocatalyst, for example, anatase type titanium oxide, rutile type titanium oxide, tin oxide,
Examples include zinc oxide, bismuth trioxide, tungsten trioxide, ferric oxide, and strontium titanate, and anatase-type titanium oxide and rutile-type titanium oxide can be suitably used. Here, as a light source used for photoexcitation of the photocatalyst, there are sunlight, indoor lighting, special lamps, and the like.
For example, a fluorescent lamp, an incandescent lamp, a metal halide lamp, a mercury lamp, a xenon lamp, a germicidal lamp and the like can be mentioned.

The photocatalyst layer in the present invention is formed from the aforementioned photocatalyst and a binder. The binder is basically not limited as long as it is a binder that can withstand the decomposition of organic substances in the catalytic activity effect by the photoexcitation of the photocatalyst, but as a specific example, it may be made of an inorganic or organic silicon compound. No. Specifically, a precursor of amorphous silica or a silane compound may be used. The precursor of the amorphous silica is an average compositional formula (OR) which is a partially hydrolyzed, dehydrated polycondensate of tetraalkoxysilane.
xSiOy (0 <x ≦ 4, 0 ≦ y <2), such as a tetrafunctional siloxane resin, silanol, and a silanol resin which is a dehydration-condensation polymer thereof. Examples of the silane compound include methyltrimethoxysilane and methyltriethoxysilane. ,
Examples include methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, and the like. A silane coupling agent can be further added to the photocatalyst layer. The silane coupling agent has a hydrocarbon group bonded directly to a silicon atom or via an oxygen atom or an —OCO— group, and at least one of these hydrocarbon groups has a double bond or a halogen atom. , An epoxy group, an acid anhydride group, an alkoxycarbonyl group, an amino group, an acroyl group, a methacryloyl group, an acrylamino group, a methacrylamino group or a haloacylamino group. Among them, compounds having an epoxy group or an amino group are particularly effective. The amount of the silane coupling agent added to the photocatalyst layer is preferably from 0.1% to 5%.

An antibacterial metal such as Ag, Cu, or Zn may be further added to the photocatalyst layer. Similarly, a platinum group metal such as Pt, Pd, Ru, Rh, Ir, and Os may be added to the photocatalyst layer.

In the present invention, after providing the above-mentioned easy-adhesion layer on a plastic film, a photocatalyst layer can be provided on the layer. For example, a composition (specifically, an anatase-type titanium oxide sol, a silica sol and an ethanol-diluted product of trimethoxysilane) obtained by dispersing and mixing an amorphous silica precursor and anatase-type titanium oxide particles on the easy-adhesion layer. After the application, amorphous silica is generated by a curing reaction, and the generated amorphous silica is used as a binder to fix anatase type titanium oxide particles to form a photocatalytic layer. Alternatively, a mixture of unreacted or partially cured silicone or silicone precursor and anatase-type titanium oxide sol are mixed, and if necessary, the silicone precursor is hydrolyzed. The photocatalyst layer composed of anatase-type titanium oxide particles and silicone can be formed by applying the above solution and subjecting the hydrolysis product of the silicone precursor to dehydration-condensation polymerization by a method such as heating. Coating methods include spray coating, dip coating, follow coating, spin coating,
Roll coating, gravure coating, reverse coating, comma coating, lip coating, offset gravure coating, die coating, and the like. The thickness of the photocatalyst layer is
The thinner the better, the better, and preferably 10 μm or less. In particular, 0.2 μm or less is particularly preferable. On the surface of the photocatalyst layer, a protective layer or other functional film which can be made hydrophilic and which is resistant to friction or corrosion may be further provided.

The photocatalyst sheet of the present invention is preferably provided with an adhesive layer on the opposite side of the photocatalyst layer. The pressure-sensitive adhesive is not particularly limited, but may be acrylic, urethane, rubber,
Examples include pressure-sensitive adhesives such as styrene, isoprene, styrene, and silicone. In addition, those obtained by appropriately blending additives such as a crosslinking agent, a filler and a tackifier to these pressure-sensitive adhesives may be used.

The photocatalyst sheet with a protective layer of the present invention can protect the photocatalyst layer by providing a heat-meltable resin layer substantially non-adhesive to the photocatalyst layer on the photocatalyst layer. Further, a plastic film exhibiting a melting temperature higher than the melting temperature of the heat-fusible resin forming the layer may be further provided on the heat-fusible resin layer. By coating the photocatalyst layer with a heat-meltable resin or the like that is substantially non-adhesive to the photocatalyst layer, a step of applying an adhesive to the non-photocatalyst layer side of the sheet-like substrate, or on a release sheet In the step of laminating the formed pressure-sensitive adhesive layer on the non-photocatalyst layer side of the sheet-like base material, and in the step of attaching and constructing the photocatalyst sheet with the pressure-sensitive adhesive layer to an adherend such as a signboard, the photocatalyst layer is not damaged. After sticking and applying to an adherend, without leaving an adhesive or the like on the photocatalyst layer surface, a protective layer from the photocatalyst layer, that is, a heat-meltable resin layer, or a heat-meltable resin layer And the plastic film on the hot-melt resin layer can be peeled off. The hot-melt resin layer is
Since the adhesive layer only adheres to the photocatalyst layer due to the adhesive force at the time of thermal melting, the adhesive layer on the back of the photocatalyst sheet can be easily peeled off from the photocatalyst layer after being adhered to the adherend.

The photocatalyst sheet with a protective layer of the present invention can be obtained, for example, by the following two methods. A method in which a thermofusible resin is directly melt-extruded onto a photocatalyst layer provided on a sheet-like substrate (single extrusion method, tandem extrusion method, etc.), and a thermofusible resin layer is laminated on the photocatalyst layer. A heat-meltable resin substantially non-adhesive to the photocatalyst layer provided on the sheet-like substrate, a plastic film exhibiting a melting temperature higher than the melting temperature of the heat-meltable resin,
A method of melt-extruding between the photocatalyst layer and laminating a heat-meltable resin layer and a non-meltable plastic film on the photocatalyst layer (hereinafter, referred to as sandwich lamination method).

The hot-melt resin used in the present invention is a resin which is substantially adherent to the photocatalyst layer, is preferably a non-polar resin, and is preferably an olefin resin or a fluorine resin. Specifically, low-density polyethylene, linear low-density polyethylene, ultra-low-density polyethylene, medium-density polyethylene, high-density polyethylene, polypropylene, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, fluororesin , Polyester-based resins, and polyvinyl alcohol. Among them, low density polyethylene and linear low density polyethylene are desirable. still,
Acid-modified olefins such as ethylene-acrylic acid copolymers and maleic acid-modified olefins can also be used, but are less desirable because they have a polar group inside. In the case of a polyethylene-based resin, it is preferable to extrude the resin at 250 to 320 ° C. When forming the heat-fusible resin layer, various additives can be added in addition to the above-mentioned resin. However, low-molecular-weight additives exhibiting tackiness at around room temperature or additives having a low glass transition temperature can be used. It is desirable not to use agents.

The non-melting plastic film used in the sandwich laminating method exhibits a melting temperature higher than the melting temperature of the above-described hot-melt resin, and does not substantially melt under the conditions when the hot-melt resin is melt-extruded. The film is not particularly limited as long as it is a film, and specific examples thereof include a polyethylene terephthalate film, a stretched polyethylene film, a stretched polypropylene film, a polyvinyl alcohol film, a nylon film, a polyethylene naphthalate film, and a polyimide film. It can be appropriately selected in consideration of the type of the meltable resin and the melt extrusion conditions such as the melt extrusion temperature, speed, and film thickness. That is, in the melt extrusion side switch lamination method, "the temperature at which substantially no heat melting is performed" may be any temperature at which the form of the non-meltable film can be maintained when the meltable resin is brought into contact with the non-meltable film at a high temperature. For example, since a stretched polyethylene film has a higher melting temperature than an unstretched polyethylene film, polyethylene can be melt-extruded sandwich-laminated between the photocatalytic layer and the stretched polyethylene film as a hot-melt resin. In addition, at the time of sandwich lamination,
Since the hot-melt resin cools down in a very short time, a plastic film with a relatively low melting point and softening point can be used as a non-meltable film as long as the form of the film is not impaired. As the film, it is preferable to use a film exhibiting a melting point or a softening temperature higher than the melting point or the softening point of the hot-melt resin extruded. Further, it is preferable that the hot-melt resin is melt-extruded at a temperature lower than the melting point or softening temperature of the non-meltable film. In the case of the sandwich laminate of the present invention, low-density polyethylene is used as the hot-melt resin, and biaxially stretched polyethylene terephthalate film is used as the non-meltable plastic film.
It is particularly preferred to melt extrude at 330 ° C.

Prior to the sandwich lamination, it is desirable to apply a coating agent having an easy adhesive property such as an anchor coating agent and improving the adhesive force on the non-melting film. The anchor coating agent is not particularly limited, but is not particularly limited, such as a urethane type, an imine type, an alkyl titanate type, and a butadiene type. Incidentally, the above-mentioned anchor coating agent must not be present on the photocatalyst layer. Because
This is because the protective layer, which is a feature of the present invention, may not be easily peeled when the protective layer is peeled off, or the anchor coating agent may remain on the photocatalyst surface after the protective layer is peeled off.

[0024]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples unless it exceeds the gist. In addition, the test method in an Example is as follows. Protective layer peeling strength: A melt-extruded bonded sample or a sandwich-laminated bonded sample was heated at 25 ° C.
Using a tensile strength tester, the peel strength of the photocatalyst layer and the protective layer at 180 ° peeling was determined for a sample stored for one week under the condition of 50% RH and cut into a width of 25 mm. (Pulling speed: 300 mm / min) Photocatalyst surface contamination: The surface of the photocatalyst layer after peeling off the protective layer was observed with an electron microscope for the presence or absence of residual deposits on the surface.

Example 1 A polyethylene terephthalate film (Teijin Tetron film HB) having a thickness of 50 μm
Primer paint (Shin-Etsu Silicone, PC-7)
A) is applied at 120 ° C., 2
After drying for 0 minutes, the film was covered with a primer resin layer. Next, a silicone-based hard coating agent (Shin-Etsu Silicone, KP-85) was applied on the primer layer by a flow coating method, and dried at 120 ° C. for 60 minutes to form a hard coat layer. Next, a corona treatment was performed on the hard coat layer. 9 wt% of anatase type titanium sol <Nissan Chemical TA-15 solid content 15 wt%> and 16 wt% of silica sol <Nippon Synthetic Rubber Glaska A Solution Solid Content 13 wt%> was diluted with ethanol, and further diluted with ethanol. A titanium oxide-containing coating composition obtained by adding 3 parts by weight of methoxysilane <Nippon Synthetic Rubber Glaska B Solution> is applied to the corona-treated surface by a die coating method, and then cured by heat treatment at 120 ° C. for 30 minutes, A photocatalyst layer was formed on a polyethylene terephthalate film. The surface of the photocatalyst layer was melt-extruded and coated with a low-density polyethylene (Mitsui Chemicals, Mirason 11P) at 280 ° C. using an extruder without applying an anchor coat. (Thickness: 50 μm) When the low-density polyethylene film as the protective layer was peeled off and the peel strength of the protective layer was measured, the protective layer could be peeled off without any resistance, and the measured value was 50 g / 25 mm. In addition, when the photocatalyst surface contamination was examined, no adhered foreign matter was found in the photocatalyst layer.

Example 2 Using the polyethylene terephthalate film provided with the photocatalyst layer obtained in Example 1, a photocatalyst layer not coated with an anchor coat and a urethane anchor coat agent (Toyo Morton AD335A)
E & CAT-10 0.5μm dry thickness) 2
28mm with extruder between 5μm polyethylene terephthalate film (Teijin Tetoron Film HS)
At 0 ° C, low density polyethylene (Mitsui Chemicals Mirason 11
P) was melt extruded and sandwich-laminated. (Thickness: 25 μm) The composite film of polyethylene terephthalate and low-density polyethylene as the protective layer was peeled off, and the peel strength of the protective layer was measured.
It was 5 g / 25 mm. In addition, when the photocatalyst surface contamination was examined, no adhered foreign matter was found in the photocatalyst layer.

Comparative Example 1 A 25 μm polyethylene terephthalate film (Teijin Tetron film HS) used in Example 2 was applied to a slightly tacky adhesive (BP manufactured by Toyo Ink Manufacturing Co., Ltd.).
S-5226 / BXX5134) with a dry film thickness of 30 μm
After coating, the photocatalyst layer of the polyethylene terephthalate film provided with the photocatalyst layer obtained in Example 1 was bonded to the slightly tacky pressure-sensitive adhesive layer. The polyethylene terephthalate film with the pressure-sensitive adhesive layer as the protective layer was peeled off, and the peel strength of the protective layer was measured. As a result, there was a very strong resistance, and the measured value was 250 g / 25 mm. When the photocatalyst surface contamination was examined, it was found that the pressure-sensitive adhesive remained in the photocatalyst layer.

[0028]

According to the present invention, the pressure-sensitive adhesive layer can be provided without damaging the photocatalyst layer, and can be adhered and constructed on an adherend such as a signboard, and can be adhered and constructed on an adherend. After this, even when the protective layer was peeled off, a photocatalyst sheet with a protective layer was obtained in which no adhesive substance or the like remained in the photocatalytic layer and the function of the photocatalyst was maximized.

Continued on the front page F-term (reference) 4F100 AA21B AK01C AK01D AK06 AK42 AK52 AR00B AR00E AT00A BA03 BA04 BA05 BA07 BA10A BA10B BA10D BA10E BA26 CB03C CC00 EH23 EJ55 EJ65 JB05 JC00 JK12 JL08BABA18A13A BB02A BB04A BB06A BC12A BC22A BC25A BC31A BC32A BC35A BC50A BC60A BC66A BC71A BC72A BC73A BC74A BC75A BE08A BE08B BE37A BE37B EA07 EA11 EB15Y ED02 ED03 EE01 EE06 FA01 FB71 FB23FB

Claims (7)

[Claims] 1. A photocatalyst sheet with a protective layer comprising a sheet-like substrate, a photocatalyst layer, and a heat-meltable resin layer substantially non-adhesive to the photocatalyst layer, laminated in this order. 2. A sheet-like substrate, a photocatalyst layer, a heat-meltable resin layer substantially non-adhesive to the photocatalyst layer, and a plastic film exhibiting a melting temperature higher than the melting temperature of the heat-meltable resin layer. Are laminated in this order. 3. The photocatalyst sheet according to claim 1, wherein the photocatalyst layer contains titanium oxide as an essential component. 4. The protective layer according to claim 1, wherein a pressure-sensitive adhesive layer and a release sheet are laminated in this order on a surface of the sheet-shaped substrate which is not in contact with the photocatalyst layer. With photocatalyst sheet. 5. A photocatalyst layer is laminated on one surface of a sheet-like substrate, and then a hot-melt resin substantially non-adhesive to the photocatalyst layer is melt-extruded onto the photocatalyst layer. Of producing a photocatalyst sheet with a protective layer. 6. A photocatalyst layer is laminated on one surface of a sheet-like substrate, and then a heat-meltable resin substantially non-adhesive to the photocatalyst layer is heated to a temperature higher than the melting temperature of the heat-meltable resin. A method for producing a photocatalyst sheet with a protective layer, comprising: performing a melt extrusion sandwich lamination between a plastic film having a melting temperature and the photocatalyst layer. 7. The method for producing a photocatalyst sheet according to claim 5, wherein the photocatalyst layer contains titanium oxide as an essential component.